The synthesis of compounds (II) and (III) are described in Tetrahedron 1997, 53, 3347.

The syntheses of either the free amine or the hydrochloride salt of compound (IV) are described in WO99/05142, Tetrahedron Lett., 2000, 41, 9537 and Synth. Commun. 2001, 31, 2849. The synthesis of a diastereomerically pure dibenzoyl-L-tartrate salt of compound (IV) is described in WO 2009/064249.

The synthesis of benzyl [(3aS,4R,6S,6aR)-6-hydroxy-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-yl]carbamate (VI) is described in WO00/34283 and WO 01/92263.